The present invention relates to a motorcycle tire, more particularly to a block tread pattern capable of satisfying both of grip performance on hard ground surface and grip performance on soft ground surface at a highly sophisticated level and suitable for riding on rough terrain.
In a motorcycle tire for riding on rough terrain, for example, for use in motocross, the tread portion is usually provided with a block pattern.
When riding on hard ground surface, for example, dry unpaved road surface, such block pattern tire exert its grip performance by digging edges of the blocks into the ground surface, namely, by the edge effect of the blocks.
From a standpoint of increasing the edge effect, it is desirable that blocks are arranged so as to stagger along circumferential lines parallel with the tire circumferential direction, namely, not to align in the tire circumferential direction.
When riding on soft ground surface such as muddy unpaved road, it is desirable for better grip performance to allow the blocks to penetrate into the soft ground surface by facilitating the ejection of mud or soil plugged between the blocks.
From a standpoint of facilitating the ejection of mud or soil, it is desirable that the blocks are arranged in circumferential rows to form a circumferentially continuously extending grooved part (linear groove) between the block rows.
In this case, however, the edge effect is sacrificed and the grip performance on hard ground surface is deteriorated.
Thus, it is difficult to satisfy both of the grip performance on hard ground surface and the grip performance on soft ground surface (muddy road).